Multifunctional nanomaterials for dental photo-theranostics

Recent studies highlight the significant promise of nanomaterial-mediated diagnostic and therapeutic strategies for managing dental diseases. Among these, photo-responsive technologies have emerged as non-invasive, targeted, and spatiotemporally controllable modalities capable of delivering efficient and site-specific interventions. The oral cavity's inherent accessibility to external light sources makes it an ideal environment for light-triggered therapeutic strategies, enabling precise control over treatment activation while minimising systemic exposure and side effects. When activated by specific wavelengths of light, photo-responsive nanomaterials trigger physicochemical reactions that can modulate the local microenvironment or visualise early-stage lesions with high precision. Advances in materials science and nanotechnology have enabled the rational design of diverse light-activated nanomaterials, including inorganic nanoparticles, organic photosensitisers, and hybrid nanocomposites, tailored for dental applications. This review provides a comprehensive overview of representative light-responsive nanomaterials with therapeutic and/or diagnostic functionality in the oral context. We investigate their mechanisms of action under light stimulation, analyse their performance relative to conventional and non-photoactivated treatments, and appraise their translational potential. In addition, we explore the current challenges facing the clinical implementation of light-activated nanomedicine in dentistry, including biocompatibility, penetration depth, and complex oral microenvironments. Finally, we offer recommendations on the design principles and treatment strategies for next-generation photo-theranostic platforms, aiming to inspire innovative approaches to dental disease management by integrating nanotechnology and photomedicine.